Process of manufacturing nitrogen compounds.



No. 657,937. Patented Sept. l8, I900.

C. B. JACOBS.

PROCESS OF MANUFACTURING NITROGEN COMPOUNDS.

(Application filed Apr. 7, 1899.) (No Model.)

Fig 2 1 I f 741 a 6 4 70 w Q ITNESSES I :1 7L /NVENTO/? a614- W. "t &fl/rCm ll/v By ATTORNEYS UNITED STATES PATENT OFFICE.

CHARLES E. JAooBs, or- EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNEASSIGNMENTS, TO THE OYANIDE COMPANY, or NEW JERSEY.

PROCESS OF MANUFACTURING NITROGEN COMPOUNDS.

s'PEcIEIcATIoN forming part of Letters Patent No. 657,937, datedSeptember 18, 1900.

Application filed April '7, 1899. Serial No. 712,054- (No specimens.)

To all whom, it may concern.-

Be it known that I, CHARLES B. JACOBS, a citizen of the United States,residing at East Orange, in the county of Essex and State of New Jersey,have invented certain new and useful Improvements in Processes ofManufacturing Nitrogen Compounds, of which the following is aspecification.

The invention relates to the synthetic proro duction of nitrogencompounds by the treatment of carbids and to the production of carbid ina form suitable for such treatment.

The immediate object of the invention is the production ofalkaline-earth metal cyr 5 anids, more especially the cyanid of bariumfor use as such or for conversion into the more commonly used cyanids ofsodium or potassium.

I have discovered that when a carbid of an alkaline-earth metal is mixedwith coarselyground porous carbon or coke and heated to fusion in anelectric furnace the resulting product is an extremely-porous frittedmass of carbid and free carbon, and that if this 2 5 porous material besubjected to the action of nitrogen or a nitrogen-bearing gassuch, forinstance, as producer-gas or atmospheric air while still hot, but afterit has cooled below the temperature of formation and of fusion 0 of thecarbid a combination of the nitrogen and the carbon of the carbid iseffected, forming a cyanid of the base metal of the carbid. The reactiontakes place with especial facility and completeness with barium carbid.When 3 5 in the above-described porous condition, ba-

rium carbid'is an unsaturated compound and well adapted therefore totake up nitrogen,two atoms of which are absorbed by each molecule of thecarbid. The reaction does not take place 40 at the temperature at whichthe carbid is formed in the electric furnace or, indeed, at anytemperature above the fusing-point of the carbid. In fact, at such hightemperature the efiect would be to at once decompose any nitrogencompound that might be already present. It is therefore necessary tofirst produce the carbid at a high temperature and then to subject thecarbid at a lower temperature to the action of nitrogen. This lowertemperature being below the fusing-point of the carbid, it is alsonecessary to provide means for bringing the nitrogen effectively intocontact with same at such lower temperature by maintaining the wholemass in a porous condition.

My invention therefore consists generally in the production of a porouscarbid by providing in the mass of carbid cores, bases, or lumps ofcomparatively-infusi ble material on which the carbid is distributedwith intervening interstices and in the treatment of such porous masswith nitrogen at a suitable temperature to induce chemical action andmore particularly in the treatment of barium carbid by such a process.

The accompanying drawings represent an electric furnace suitable forcarrying out my invention.

Figure l is a partly-sectional elevation of the invention, and Fig. 2 avertical section at right angles to Fig. 1. 0

In carrying out the invention I introduce the carbid in a granulatedform mixed with coke coarsely ground into the circuit of an incandescentelectric f urnace,thereby obtaining the necessary heat from theresistance 7 5 offered by the charge to the passage of the current tocause the carbid to assume a condition of pasty fusion, which,owing tothe coarse cokepresent, brings the charge into a condition of extremeporosity, in which state barium carbid under the influence of heatcombines with nitrogen, rapidly forming barium cyanid by a reactionwhich will be understood from the following structural equation:

The carbids of the bivalent elements, such as the alkaline-earth metals,are particularly well adapted for this reaction, as they are unsaturatedcompounds, each carbon atom present having four chemical bonds oraffinities, only two of which can be satisfied by the bivalent earthmetal leaving the three remaining 5 bonds of each carbon atom to besatisfied by the affinity of the carbon atoms for each other. WVith suchcompounds it is comparatively easy to pass from the unsaturated to thesaturated state by the addition of new elements carrying the lowestnumber of satisfying bonds or affinities. When nitrogen is passedthrough the heated mass of porous carbid, each molecule of carbid takeson two atoms ofnitrogen, becoming a saturated compound, the three bondsof each carbon atom being replaced by the three bonds of each of the twonitrogen atoms, since the carbon has a stronger affinity for thenitrogen than for itself. The barium cyanid thus produced may beseparated from the excess of coke or carbon in the mass by solution andrecrystallization and used directly for the ordinary purposes to whichsoluble cyanids are applied; or it may be converted into the morecommonly used sodium or potassium cyanid by mixing a solution of thebarium cyanid with a carbonate of the alkaline metal and filtering offthe precipitated barium carbonate for further use in the production ofbarium cyanid and evaporating the solutions of potassium or sodiumcyanid thus obtained to a point at which crystallization takes place oncooling.

The process is most effectively carried out in the rotary carbid furnacedescribed in United States Patent No. 597,945, granted to Charles S.Bradley, January 25, 1898, so modified that nitrogen may be introducedby means of twyers under sufficient pressure to cause it to pass throughthe cooling mass of porous carbid from the point at which the product isdischarged from the furnace to the electrodes between which the carbidis first heated, thus insuring a nitrification period of the longestpossible duration without interfering in any way with the continuousoperation of the process. Such a furnace is shown in the accompanyingdrawings,wherein 1 represents a main shaft supported on bearings 3 andcarrying by spokes 2 a rim 4, formed as the inner half of an annulardrum, removable shells or covers at being attached to the rim tocomplete such annular drum, which serves as the receptacle for thematerials operated upon during the process. In practice these shells areattached to the lowerhalf of the rim, being added to one side andremoved from the other as the wheel-frame 2 3 rotates. Two carbonterminals 5, with suitable feeding devices 5, are located so that thecarbons may project into the annular receptacle, as indicated in Fig. l.6 and gearing 7, are provided for slowly rotating the annularreceptacle, the mechanism, as so far described, being similar to thatshown in the patent above referred to. To adapt this apparatus forcarrying out my process, pipes or tubular connections 8 may be providedat a plurality of points in the annular rim and communicating with ahollow bore in the shaft 1, said bore being connected by a pipe 9 with asuitable source of nitrogen under pressure, here indicated as a tank 10.

Valve devices are provided for cutting off the supply of nitrogen fromthose parts of the annular rim which are unoccupied by carbid material,and for this purpose I have shown a valve formed by an extension 11 ofpipe 9,Which, being stationary, acts as a valvestem in cooperation withthe openings of pipes 8, so that the nitrogen is admitted to the carbidmaterial (indicated at as) shortly after the production of the carbidbetween the electrode-terminals and after the material has begun tocool, and the supply of nitrogen is maintained in contact with thecarbid after the latter has cooled below its melting-point, being onlycut off when the carbid finally cools to ordinary temperatures. Inasmuchas the reaction with nitrogen only takes place at temperatures below themelting-point of the carbid, it is' essential to the process that thecarbid material should be maintained in a more or less porous condition,since if it were allowed to melt into a compact mass it would beimpenetrable to the nitrogen.

To avoid the expense of manufacturing barium carbid in a separateoperation for use in the process, I prefer to use as my raw material forintroduction into the rotary furnace a mixture of barium carbonate orbarium hydrate with sufficient carbon to produce a carbid and also anexcess of coarsely-ground coke to give the product the necessary degreeof porosity. The process then takes place in two steps. In the firststep porous barium carbid is transitorily formed between the electrodesand passes over to the cyanid by absorption and conversion during thecooling or nitrification period, as the nitrogen ascends through themass of porous carbid during the rotation of the furnace. By this meansthe operation in the rotary furnace renders the formation of carbid andits conversion into cyanid simultaneously continuous. By either methodof operation the resulting product is a fritted porous mass of crudebarium cyanid.

Vhile I prefer to use carbon as the mate rial for the refractory coresor bases on which the carbid is distributed by fusion, I mayuse anymaterial which is sufficiently refractory under the conditions of theprocess.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is Means, such as a motor 1. Theprocess of making a nitrogen compound consisting in subjecting a mixtureof carbid and coarsely-ground coke to the action of heat in an electricfurnace, whereby the carbid is caused to fuse and coat the particles ofcoke, allowing the mass to cool below the temperature of fusion of thecarbid, and subjecting the porous mass at such lower temperature to theaction of nitrogen.

2. The process of forming the cyanid of an alkaline-earth metalconsisting in subjecting bon in excess of the amount required for thethe porous mass at such lower temperature formation of oarbid to theheat of an electric to the action of nitrogen. furnace, whereby a porouscarbid composition, consisting of particles of carbon coated 5 Withcarbid, is formed, allowing the said por- Witnesses:

ous composition to cool below the tempera- A. P. KNIGHT, ture of fusionof the carbid and subjecting 1 M. V. BIDGOODA CHARLES B. JACOBS;

